Turn off audio playback of AVPlayer?

I have a AVPlayer with AVPlayerItem. What i want is to turn off the audio playback off AVPlayer. I want play just video.

Can someone help me? Thank you!

    self.avPlayerItem = [AVPlayerItem playerItemWithURL:self.videoUrl];
    self.avPlayer = [AVPlayer playerWithPlayerItem:self.avPlayerItem];
    [self.avPlayer play];
    self.avPlayer.actionAtItemEnd = AVPlayerActionAtItemEndNone;


    self.avPlayerLayer = [AVPlayerLayer playerLayerWithPlayer:self.avPlayer];
    self.avPlayerLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(playerItemDidPlayToEndTime:)
                                                 name:AVPlayerItemDidPlayToEndTimeNotification
                                               object:self.avPlayerItem];


    CGRect screenRect = [[UIScreen mainScreen] bounds];

    self.avPlayerLayer.frame = CGRectMake(0, 0, screenRect.size.width , screenRect.size.height );
    [self.view.layer insertSublayer:self.avPlayerLayer atIndex:0];

via Chebli Mohamed